Design, development and testing of a high-speed axial-flux permanent-magnet machine

Abstract

This paper will give an overview of the design, manufacturing and testing of a high speed (16000 rpm and 30 kW) AFPM synchronous machine, which is mounted inside, and as an integral part of, a flywheel; this system will subsequently be used for transient energy storage and ICE operating point optimization in an HEV. The paper focuses on the major design issues, particularly with regard to the high rotational speed, and investigates the loss mechanisms which are apparent therein, eg.iron losses, rotor losses, and friction losses. The paper describes the high-speed testing facility and includes measured results; these will be compared to calculated values.

Soft magnetic composite materials (SMCs)

“…However, these limitations were being overcome with the development of improved raw materials and new shaping technologies. These composites find increasing use in electrical motors, replacing existing laminate materials [53,56,59,65,[68][69][70][71][72][73]. These materials are being developed to provide materials with competitive magnetic properties (good relative permeability and magnetic saturation), but with high electrical resistivity [49].…”

“…To establish the design rules, one must pay attention to electromagnetic loss characteristics of SMC materials. Several different series of ironbased SMCs are: (1) pure iron powder with resin, (2) sintered iron-based powders, (3) pure iron powder with additions of Znstearate and carbon, (4) iron-based powder alloys (Fe, Ni, Co, Si), (5) commercially available iron powder "Somaloy" [70][71][72][73][74][75]. Among these, the composite materials minimize fringing flux due to their distributed air gap.…”

Performance comparison between low-speed axial-flux and radial-flux permanent-magnet machines including mechanical constraints

“…From this it follows the assumption that the axial length of the AFIPM type machines has to include also the length of the fixing parts. These fixing parts may be manufactured simply by using rectangular steel bars or alternatively by integrating the cooling channels into the supporting structure, as demonstrated in [9], which makes implementing of the additional parts more attractive.…”

Thermal Analysis on Radial Flux Permanent Magnet Generator (PMG) using Finite Element Method

“…0 C and for force convection, it is around 30-300 W/m 2 . 0 C [12]. In this research the average coefficient of the convection is 18 W/m 2 .…”